When Harvard symbologist Robert Langdon introduces his students to the wonders of their own country, he pretends surprise that more of his students have been to Europe than to their own capital. "Why do you think that is?" he asks.

"No drinking age in Europe!" is the quick reply.

Readers of "The Lost Symbol," Dan Brown's third novel featuring the academic action hero Langdon, will probably beat feet to Washington, D.C., as Langdon makes the persuasive case that our own history, art and architecture, that our American symbology, rivals anything to be found in Paris or Rome. Tour buses, start your engines!

When Langdon is asked to do a favor for an old friend, historian and philanthropist Peter Solomon, he is happy to oblige. Solomon is now secretary of the Smithsonian, but when Langdon shows up to give a lecture, there's no audience. (We can be sure this would never happen to Dan Brown!) The true purpose of Langdon's visit becomes clear when a severed hand, bearing Solomon's ring marking his rank as a 33rd degree Mason, as well as the iconography of the Hand of the Mysteries, proffers both an invitation and a clear message: Solomon has been kidnapped.

Solomon's kidnapper, Mal'akh, is a freakishly devout conspiracy theorist in search of a final mystery, the lost symbol, that will complete the tattooed canvas that is his body. That knowledge is what he demands as ransom for Peter Solomon. Langdon is aided in his quest for this arcane knowledge by Solomon's sister, Katherine, who has her own lab in a Smithsonian facility in Maryland, the Institute of Noetic Science, testing the boundaries between faith and science, pushing the envelope of human potential.

The capital gang also includes various members of the CIA, including the wickedly determined Inoue Sato (in a clear casting call for Linda Hunt), the architect of the Capitol (not whom you might think), the dean of the National Cathedral, and a number of law enforcement officers and genius computer hackers. But Mal'akh is elusive and smart and has had years to plan his quest.

The Freemasons have a long and provocative history and Brown makes the most of it, including Freemasonry's role in the lives of many of America's Founding Fathers. Readers of "The Lost Symbol" will never look at their national monuments the same way again, will marvel at the intricacies of the Capitol Rotunda, wonder if there are "undisclosed locations" in the Senate sub-basement, savor the view from the Washington Monument, cherish the treasures of the Smithsonian. Brown gives us a guided tour of American iconography, from paintings such as "The Apotheosis of George Washington," right down to that old chestnut, the pyramid on the dollar bill and Benjamin Franklin's "magic squares," sure to appeal to Sudoku fans. Numerology, alchemy, astrology -- they're here too.

"The Lost Symbol" includes all the basic formulaic elements of Brown's fiction: He takes a well-known location, renders its treasures in the new light of an occult framework, sets Langdon on a brief but intense quest to save a life, pitting him against creative evildoers for whom violence itself is a work of art. Now add to that sly and amusing references to Brown's previous work and his great success, irresistible for an author whose work is touted as "the economic stimulus package" for the publishing industry.

But one of the daring things about Brown's fiction is that he's not afraid to make the quest for knowledge -- even the very idea of reading and the places we do it -- sexy and dangerous. Only Robert Langdon could say, "I've got to get to a library!" in "The Da Vinci Code." Remember the dangerous Vatican archives in "Angels and Demons"? In "The Lost Symbol," there's a late-night visit to the Library of Congress, itself a kind of cathedral. Ancient manuscripts hold answers for present predicaments in Langdon's world.

Books filled with "the simple transformative truth of the ancient teachings" are only some of the treasures to be found in the quest for the lost symbol. Langdon is refreshingly old-fashioned in his inability to "send a Twitter," his idea that "¤'Google' is not a synonym for 'research.'¤" Peter Solomon reminds Langdon that skepticism can be both a strength and a weakness. But Langdon can read the world around him and because of that, he -- surprisingly, sweetly -- finds hope on the horizon of an American landscape at dawn. Beyond the furious, fast-paced entertainment that is "The Lost Symbol," that is Dan Brown's gift to readers.